Results.txt

False : Evil time is 668
True : Good time is 261

slow.cs

    public class NotSureWhatThisDoesButItIsSlow
    {
        private readonly ITestOutputHelper output;

        public NotSureWhatThisDoesButItIsSlow(ITestOutputHelper output)
        {
            this.output = output;
        }

        IndexTriangle[] tris = new IndexTriangle[]
                                {
                                    new IndexTriangle(0,1,2), 
                                    new IndexTriangle(3,4,5), 
                                    new IndexTriangle(6,7,8), 
                                    new IndexTriangle(9,10,11), 
                                    new IndexTriangle(12,13,14), 
                                };

        Point3D [] vectors = new Point3D[]
                              {
                                  new PointNormalUv(0,0,0,1,1), 
                                  new PointNormalUv(1,0,0,2,2), 
                                  new PointNormalUv(0,1,1,3,3), 
                                  new PointNormalUv(0,0,0,1,1), 
                                  new PointNormalUv(1,0,0,2,2), 
                                  new PointNormalUv(0,1,1,3,3), 
                                  new PointNormalUv(0,0,0,1,1), 
                                  new PointNormalUv(1,0,0,2,2), 
                                  new PointNormalUv(0,1,1,3,3), 
                                  new PointNormalUv(0,0,0,1,1), 
                                  new PointNormalUv(1,0,0,2,2), 
                                  new PointNormalUv(0,1,1,3,3), 
                                  new PointNormalUv(0,0,0,1,1), 
                                  new PointNormalUv(1,0,0,2,2), 
                                  new PointNormalUv(0,1,1,3,3), 
                                  new PointNormalUv(0,0,0,1,1), 
                                  new PointNormalUv(1,0,0,2,2), 
                                  new PointNormalUv(0,1,1,3,3), 
                              }; 


        private static bool Fn(Point3D[] _param0, IndexTriangle[] _param1, double _param2, double _param3, int _param4)
          {
            var pointNormalUv1 = (PointNormalUv) _param0[_param1[_param4].V1];
            var pointNormalUv2 = (PointNormalUv) _param0[_param1[_param4].V2];
            var pointNormalUv3 = (PointNormalUv) _param0[_param1[_param4].V3];
            var point2D1 = new Point2D(pointNormalUv1.U * _param2, pointNormalUv1.V * _param3);
            var point2D2 = new Point2D(pointNormalUv2.U * _param2, pointNormalUv2.V * _param3);
            var point2D3 = new Point2D(pointNormalUv3.U * _param2, pointNormalUv3.V * _param3);
            var length1 = new Vector2D(point2D1, point2D2).Length;
            var length2 = new Vector2D(point2D2, point2D3).Length;
            var length3 = new Vector2D(point2D3, point2D1).Length;
            var num = (length1 + length2 + length3) / 2.0;
            return length1 * length2 * length3 / (8.0 * (num - length1) * (num - length2) * (num - length3)) < 1000.0;
          }

        private static bool Fn2(Point3D[] _param0, IndexTriangle[] _param1, double _param2, double _param3, int _param4)
          {
            var pointNormalUv1 = (PointNormalUv) _param0[_param1[_param4].V1];
            var pointNormalUv2 = (PointNormalUv) _param0[_param1[_param4].V2];
            var pointNormalUv3 = (PointNormalUv) _param0[_param1[_param4].V3];
            var point2D1 = (pointNormalUv1.U * _param2,  pointNormalUv1.V * _param3);
            var point2D2 = (pointNormalUv2.U * _param2, pointNormalUv2.V * _param3);
            var point2D3 = (pointNormalUv3.U * _param2, pointNormalUv3.V * _param3);

            double dist((double x, double y) d0, (double x , double y) d1) => Math.Sqrt( d0.x * d1.x+ d0.y * d1.y );
            var length1 = dist(point2D1, point2D2 );
            var length2 = dist(point2D2, point2D3);
            var length3 = dist(point2D3, point2D1);
            var num = (length1 + length2 + length3) / 2.0;
            return length1 * length2 * length3 / (8.0 * (num - length1) * (num - length2) * (num - length3)) < 1000.0;
          }

        [Fact]
        public void FactName()
        {
            var s = Stopwatch.StartNew();
            var b = true;
            for (int i = 0; i < 10000000; i++)
            {
                b = b & Fn( vectors, tris, i, i + 1, i%5);
            }
            GC.Collect();
            output.WriteLine( $"{b} : Evil time is {s.ElapsedMilliseconds}" );

            s = Stopwatch.StartNew();
            b = true;
            for (int i = 0; i < 10000000; i++)
            {
                b = b & Fn2( vectors, tris, i, i + 1, i%5);
            }
            GC.Collect();
            output.WriteLine( $"{b} : Good time is {s.ElapsedMilliseconds}" );
        }
        
    }